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authorMichael Guralnik <michaelgur@mellanox.com>2018-12-09 11:58:04 +0200
committerJason Gunthorpe <jgg@mellanox.com>2018-12-20 15:18:18 -0700
commit2e8039c656224b4a21e1947f45946d32a59bae53 (patch)
tree90738b202e103845640916c727fae63559901aca /drivers/infiniband/core/uverbs_ioctl.c
parentIB/rxe: Reuse code which sets port state (diff)
downloadlinux-dev-2e8039c656224b4a21e1947f45946d32a59bae53.tar.xz
linux-dev-2e8039c656224b4a21e1947f45946d32a59bae53.zip
IB/core: uverbs copy to struct or zero helper
Add a helper to zero fill fields before copying data to UVERBS_ATTR_STRUCT. As UVERBS_ATTR_STRUCT can be used as an extensible struct, we want to make sure that if the user supplies us with a struct that has new fields that we are not aware of, we return them zeroed to the user. This helper should be used when using UVERBS_ATTR_STRUCT for an extendable data structure and there is a need to make sure that extended members of the struct, that the kernel doesn't handle, are returned zeroed to the user. This is needed due to the fact that UVERBS_ATTR_STRUCT allows non-zero values for members after 'last' member. Signed-off-by: Michael Guralnik <michaelgur@mellanox.com> Reviewed-by: Majd Dibbiny <majd@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/core/uverbs_ioctl.c')
-rw-r--r--drivers/infiniband/core/uverbs_ioctl.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index 3cc46447240e..8c81ff698052 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -751,3 +751,14 @@ int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
return 0;
}
EXPORT_SYMBOL(_uverbs_get_const);
+
+int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
+ size_t idx, const void *from, size_t size)
+{
+ const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
+
+ if (clear_user(u64_to_user_ptr(attr->ptr_attr.data),
+ attr->ptr_attr.len))
+ return -EFAULT;
+ return uverbs_copy_to(bundle, idx, from, size);
+}